Telephone



April 10, 1934. w OSBORNE 1,954,547

TELEPHONE Filed June 29, 1932 a 55 and from the line.

Patented Apr. 10, 1934 nmrsn srArss TELEPHONE Ralph Willoughby Osborne, Toronto, Ontario, Canada Application June 29, 1932, Serial No. 620,001

Claims.

My invention relates to telephones of the local battery type which require alternating current means for signalling, and more particularly applies to portable telephones of the type used by 5 linemen for communicating or testing from any point along a telephone line.

The object of my invention is to provide a telephone that is readily. adaptable to having the parts to which the user comes in contact insul lated from the line, so that the instrument may be used in connection with lines subjected to extraneous voltage with safety.

A further object of my invention is to provide a portable telephone insulated for protection from extraneous voltage which is light in weight comparable with instruments of existing types.

To attain these objects I utilize a device which converts energy from a battery into alternating current for signalling. As a battery is required 330 to provide energy for operating the microphone, the same battery is available for operating the signalling means which is a part of my invention.

Existing telephones of the type which require an alternating current means for signalling are equipped with a magneto generator. In the present state of the art the only feasible means of insulating the parts of such an instrument from the line, is an insulating transformer which adds greatly to the Weight and bulk of the instrument.

39 In my invention the magneto generator is replaced by a very light and simple device for converting energy from the battery into alternating current. The voltage is stepped up to the value desired by means of a transformer which is readily insulated between its primary and secondary windings to withstand a high voltage. As a transformer of suflicient capacity is of lighter weight and of smaller dimensions than a magneto generator, I am enabled by means of my invention to design an insulated portable telephone of weight and dimensions comparable with existing uninsulated instruments.

In order to understand my invention more fully reference may be had to the following description 5 and accompanying drawing in which Fig. 1 is a diagrammatic view of my invention and Fig. 2 a view of the pole-changing device for converting energy from a battery into alternating current for signalling purposes.

Referring to the drawing it will be noted that I have shown an adaptation of my invention as applied to portable telephones in that a safe and convenient means is provided for temporarily connecting and disconnecting the instrument to Referring to Fig. 1, 1 is the line, 2 an insulated pair of wires connecting the telephone with the line, 3 and 4 are clips for attaching the wires of the insulated pair of wires to the line wires 1 and are adapted to release when tension is applied to the insulated pair of wires 2, 5 is an insulated plug for attaching the insulated pair of wires 2 to the instrument by connecting it with the jack 6, 7 is a transformer having the extremities of the primary winding 8 connected to the contacting members of the jack 6, 9 is the secondary winding of the transformer 7 in circuit relation with other essential parts of the instrument, 10 is a pole-changing or converting device for converting energy from the battery 11 into alternating current and hav ing segments 12 and 13 connected respectively to taps 14 and 15 of the secondary winding 9, a neutral point 16 relative to taps 14 and 15 is connected to the battery 11 by means of cam-switch 17 through contacts 18, rotary member 19 of the pole-changing or converting device 10 carries a brush 20 with contacting member 21 normally held out of contacting engagement with segments 12 and 13 by means of spring 22, rotary member 19 is connected to the battery 11 by means of wire 23. The translating device comprising the microphone 24, induction coil 25 and receiver 26 is of conventional type and is connected in proper circuit relation with the battery 11 and the secondary winding 9 of the transformer 7 by means ofv cam-switch 17 by means of which current from battery 11 is switched from wire 27 through contacts 28, wire 29, microphone 24, wire 30, primary winding 31 of induction coil 25, wire 32 and wire 23 back to battery 11. The receiver circuit is traced from terminal 35 of the secondary winding 9 of the transformer 7, wire 36 cam-switch contacts 37, wire 38, receiver 36, wire 34, secondary winding 33 and primary winding 31 of induction coil 25, wires 30 and 39, contacts 40 of the cam-switch 17, wire 41, condenser 42, wire 43 to terminal 14 of the secondary winding 9 of the transformer 7. The polarized buzzer 44 for receiving signals is connected in circuit with the lot) secondary winding 9 of the transformer 7 from terminal 35 by means of wire 36, wire 45, buzzer 44, wire 46 contacts 47 of the cam-switch 17, wire 41, condenser 42 and wire 43 to terminal 14 of the secondary winding 9 of the transformer 7.

The cam-switch or key-switch 17 is of conventional type similar to the type shown in U. S. Patent No. 1,778,529, Oct. 14, 1930, issued to H. H. Ide, and is shown in neutral position wherein the circuit through the polarized buzzer herein described 110 is closed by means of contacts 4'7 so that signals may be received.

In Fig. 2 the mechanical arrangement of the pole-changing or converting device 10 in Fig. 1 is shown wherein 12 and 13 are the segments insulated irorn the frame 49 by insulation 48, the rotary member 19 within the segments is connected by shaft 51 to gear engaging gear 52 which is rotated by means of shaft 53 and handle 54.

The telephone functions for signalling when contacts 3'7 of cam-switch 1'? are opened thus breaking the receiver circuit, contacts 18 are closed connecting the battery 11 through wires 27 and to neutral point 16 in secondary winding 9 of the transformer 7. ihe opposite pole of the battery 11 is connected to the rotary member 19 of the pole-changing or converting device 10 through wire 23, and when the said rotary member is rotated by means of handle 54 shown in Fig. 2 the brush 21 comes in contact with segments l2 and 13 alternately by centrifugal force overcoming the tension of spring 22 and the said brush being in electrical connection with the rotary member 19 which is connected with the ba tery 11 as described, current is alternately passed fron segment 12 through wire 56, wire 43, terminal 14 a section of secondary winding 9 between terminals 14 and i6, terminal 16, wire 55, contacts 18 of the cam-switch 1'7 wire 27 to battery 11, and from segment 13 through wire 57, terminal 15, a section of secondary winding 9 between terminals 15 and 16, and terminal 16 to battery 11 as before. This application of direct current in relative alternate directions in the two sections of the secondary winding 9 of the transformer 7 between terminals 1s and 16 and 15 and 16 respectively, is in effect an alternating current and therefore an alternating voltage is induced in the windings of the transformer '7 which may be stepped up to the required voltage depending on the ratio of turns between terminals 14 and 15 of the secondary winding 9 and those of the primary winding 8 of the transformer 7.

The telephone functions for talking when contacts 18 of the cam-switch 1'7 are open, contacts 37 and 4'? are closed in the receiver circuit heretofore described, and contacts 28 are closed to complete the circuit through battery 11, microphone 24 and primary winding of the induction coil 25 as heretofore described.

While I have shown and described one embodiment of my invention as applied to portable telephones, it will be understood that various modifications and applications to the communication arts may be made without departing from the spirit and scope of the appended claims.

What I claim is:

1. In a portable telephone, a transformer having a primary winding interposed between a pair of telephone wires, a secondary winding having a telephonic translating device relatively connected to its extremities and signalling means com rising a pole-changing or converting device for applying current from a battery in alternate directions within the said secondary winding to affect an alternating voltage in the windings of the said transformer.

2. In a portable telephone, a transformer having a primary winding interposed between a pair of telephone wires, a secondary winding having a telephonic translating device relatively connected to its extremities, a pair of taps in the secondary winding and a neutral point relative thereto and signalling means comprising a pole-changing or converting device for applying current from a battery between the said neutral point and each of the said pair of taps alternately to affect an alternating voltage in the windings of the said transformer.

3. In a portable telephone, a transformer having a primary winding interposed between a pair of telephone wires, a secondary winding having a telephonic translating device relatively connected to its extremities, and a pole-changing or converting device comprising a ring divided into two segments each connected to respective taps in the said secondary winding, a rotary member within the said ring actuated by a gear and handle and carrying a brush held normally out of engagement with the said segments by a spring but adapted to make contact with the said two segments alternately by centrifugal force the said rotary member revolves and a battery connected between the said rotar' member and a necting the battery in proper circuit relation with the said pole-changing or converting device or telephonic translating means as required.

5. The combination with a portable telephone comprising a transformer having a primary winding terminating in a line-jack, a secondary winding relatively connected to telephonic translatand signalling means and a battery of a telephone line, a pole-changing device with segments, detachable twin conductors terminating at one end in a plug attachable to the said line-jack and a pair of clips at the other end for attachment to the telephone line wires and adapted to automatically release when tension is applied to the said detachable twin conductors.

RALPH WILLOUGHBY OSBORNE. 

